Question: Simplify the following expression: ${7(-2+2a)-3(-a-7)}$
Distribute the ${7}$ into the first set of parentheses: $ {7(}\gray{-2+2a}{)} - 3(-a-7) $ $ {-14+14a} - 3(-a-7) $ Distribute the ${-3}$ into the parentheses: $ -14+14a {-3(}\gray{-a-7}{)} $ $ -14+14a + {3a+21} $ Rewrite the expression to group the ${a}$ terms and numeric terms: $ {14a + 3a} {-14 + 21}$ Combine the ${a}$ terms: $ {17a} {-14 + 21}$ Combine the numeric terms: $ {17a} + {7}$ The simplified expression is $17a+7$